166 The Molluscan Family Planorhidae 



Shell (plate 76, fig. 11). 'Dextral, globose, rather solid, deeply iimbili- 

 cated; whorls three to three and one-half, convex, body-whorl very large; 

 sjiire short, apex obtuse; aperture roundly ovate; peritreme continuous, 

 forming a heavy callus on the parietal wall of the body-whorl. Grovrth 

 lines inconspicuous, surface of the shell smooth; sutures rather irregularly 

 impressed. Length 7.26 mm.; diameter 8.13 mm.' (Call, 1888, p. 147). 



Geological Horizon and Distribution. Post-pliocene (Pleistocene). 

 Tassajara Lake beds, California. 



Species Considered as Valid. Ponipholopsis ivhitei Call is the only 

 species assigned to this genus. 



Remarks. Pompholopsis differs from Parapholyx in being deeply um- 

 bilicated and in having a high spire and smaller, rounder aperture. It is 

 related to Parapholyx but appears sufficiently distinct to justify a genus. 

 A scries of shells might add greatly to our knowledge of the relationship 

 of this species. 



Genus PLANORBARIUS Froriep, 1806 

 Type by original designation Helix cornea Linn. 



1806. Planorharius Froriep, in Dumeril, Analyt. ZooL, p. 165. Type Helix cornea Linn. 

 As genus 



1810. Planorbis Moxtfort, Conch. Syst., H, p. 270. Type Planorbis corncus (Linn.). 

 Non Geoffroy or Miiller. As genus 



1840. Planorbis Swainson, Treat. Malac, p. 337. Type Planorbis corncus (Linn.). 

 As genus 



1847. CoreUis (Adanson, 1757) Gr.\y, Proc. Zool. Soc. London, p. 180. Type Pla- 

 norbis Cornells (Linn.). As genus 



1850. Spirodiscus Stein, Schn. u. Muscheln Berlin, p. 73. Type (1st species) : Planor- 

 bis corncus (Linn.) 



1855. Coretus Moquin-T.andon, Hist. Moll. Terr. Fluv. France, II, pp. 424, 445. Type 

 Planorbis corneus (Linn.) 



1870. Planorbis Dall, Ann. N. Y. Lye. N. H., IX, p. 351. Type Planorbis corncus 

 (Linn.). As genus 



1883. Spirodiscus Fischer, Man. de Conch., p. 509. Tyjie Helix corncus Linn. As 



section of Planorbis 



1884. Planorbis Tryon, S. and S. Conch., Ill, p. 106. Type Planorbis corncus (Linn.). 



As genus 



1885. Coretus We.sterlund, Fauna Pal. Reg., V, p. 64. No type cited. As subgenus 



of Planorbis 



1886. Coretus Clessin, Conch. Cab., XVII, p. 32. Type Planorbis corneus (Linn.). 



As subgenus 

 1902. Spirodiscus Westerlund, Rad. Jugoslav. Akad., 151, p. 120. Type Helix cornea 



Linn. As subgenus 

 1905. Planorbis Dall, Alaska Moll., p. 81. Type Planorbis corneus (Linn.). As genus 



1917. Planorbis Soos, Ann. Musei Nat. Hungarici, XV, pp. 37, 140. Type Planorbis 



corneus (Linn.) 



1918. Planorbis Walker, Miscel. Pub. Mus. Zool., Univ. Mich., No. 6, p. 94. Type 



Planorbis corneus (Linn.). As subgenus of Planorbis 

 1921. Planorbis Germain, Rec. Ind. Mus., XXI, pp. 6, 9. Type Planorbis corneus 

 (Linn.). As subgenus of Planorbis 



1923. Coretus (Gray 1847) Wenz, Fossil. Cat., Pars 22, p. 1421. Genotype Coretus 



corneus (Linn.). As genus 



1924. Planorbarius Kennard and Woodw.\rd, Proc. Mai. Soc. London, XVI, p. 10. Type 



Helix cornea Linn. 



